Supercomputer simulates merger of three black holes

Washington, April 9 : A team of astrophysicists has simulated for the first time the collision and merger of three black holes on a supercomputer.

The astrophysicists include Manuela Campanelli, Carlos Lousto and Yosef Zlochower-scientists in Rochester Institute of Technology's (RIT) Center for Computational Relativity and Gravitation in the US.

The same team had earlier cracked the computer code simulating two black crashing and merging together, following Einstein's theory of general relativity.

Now, their new simulation of triplet black holes evolving, orbiting and eventually colliding, confirmed a robust computer code free of limitations.

The RIT team's triple merger simulates the simplest case of equal masses and nonspinning black holes, a prerequisite for exploring configurations of unequal masses and different spins and rotations.

The center's supercomputer cluster "newHorizons" processed the simulations and performed evolutions of up to 22 black holes to verify the results.

According to Yosef Zlochower, an assistant professor in the School of Mathematical Sciences, "Twenty-two is not going to happen in reality, but three or four can happen."

"We realized that the code itself really didn't care how many black holes there were. As long as we could specify where they were located-and had enough computer power-we could track them," he added.

"We discovered rich dynamics leading to very elliptical orbits, complicated orbital dynamics, simultaneous triple mergers and complex gravitational waveforms that might be observed by gravitational wave detectors such as LIGO and LISA," said Carlos Lousto, professor in RIT's School of Mathematical Sciences.

"These simulations are timely because a triple quasar was recently discovered by a team led by Caltech astronomer George Djorgovski. This presumably represents the first observed supermassive black hole triplet," he added.